Saudi Arabia confirmed it was behind the air strike that killed a senior Houthi leader last week, with the rebels threatening to avenge his death.

Saleh al-Sammad, head of the Houthi's supreme political council, was killed on Thursday in the western province of Hodeida.

The Houthi rebels confirmed Sammad had died in an air strike on Monday.

"The heroes of the Royal Air Force were able to successfully target the leader of the Houthi militia Saleh al-Sammad," Saudi Arabia's ambassador to the United States, Prince Khaled bin Salman, tweeted late on Tuesday.

"He vowed a couple of weeks ago to make 2018 the 'year of ballistic missiles on KSA.' The response to him was a direct hit under the leadership of HRH Minister of Defense."

"This crime will not go without punishment"

- Abdul Malik al-Houthi

The Houthis are battling the Saudi-backed Yemeni government - and a military coalition spearheaded by Riyadh - for control of the impoverished country.

Salman said the strike was overseen by his brother, Crown Prince Mohammed bin Salman (MBS), after Sammad threatened a wave of missile strikes against Saudi Arabia.

MBS, who is also the Saudi defence minister, has been the driving force behind Riyadh's intervention in the devastating Yemen war.

The RSAF has targeted the second most senior Iranian-backed Houthi commander Saleh Al Sammad. He vowed couple of weeks ago to make 2018 the “year of ballistic missiles on KSA”. The response to him was a direct hit under the leadership of HRH Minister of Defense.